LightSail 2 just met its fiery end, but solar sailing is just getting started

The latest LightSail mission gave us a glimpse into the future of solar sailing.

By GEORGINA TORBET
Nov 18, 2022,

The last image taken by LightSail 2 before it re-entered the atmosphere. Image: The Planetary Society

After three years in space, the Planetary Society’s LightSail 2 mission burned up in the atmosphere on Thursday, November 17th. During its mission, the crowdfunded spacecraft made 18,000 orbits of the planet using its giant reflective sail and demonstrated that controlled solar sailing is possible.

LightSail may now be over, but it has opened the door to the use of solar sailing in space exploration. “It doesn’t fit every situation, but now it gives another arrow in the quiver of options for types of propulsion you can use,” said Bruce Betts, Chief Scientist and LightSail program manager.

LightSail 2 operated in Earth orbit, while future solar sailing missions would likely be in deep space. That makes the requirements somewhat different. “We had the challenge that’s analogous to sailing a sailboat in the harbor versus out in the ocean,” Betts said. LightSail had an easier time with issues like communications than deep space missions would but had to constantly turn to keep in orbit.

The biggest drawback in using solar sailing for space exploration is that the forces involved are so small that craft start out traveling very slowly. “The disadvantage is that you’re using a push from the sun that is really, really tiny,” Betts explained. “The push on our entire sail if it were reflecting perfectly, from the sun at Earth’s distance, is about the same force that a housefly has when it’s sitting on your hand, pushing down.” But the advantage of the method is that this force just keeps building up over time, allowing acceleration up to high speeds without using up fuel.

Upcoming programs like NASA’s NEA Scout and Advanced Composite Solar Sail System (ACS3) will also use solar sailing. The ideal targets for these kinds of missions are within the inner solar system, as the craft stays close enough to the sun to get enough force from the sunlight to keep moving and to change an orbit.

Another type of exploration solar sailing enables is entering orbits that would otherwise be impossible using conventional propulsion systems. Missions that orbit around the sun, for example, currently have to sit in very particular regions called Lagrange points to be in a stable orbit. Trying to get closer to the sun would use up too much fuel. But with a solar sail, a spacecraft can orbit closer to the sun and use its sail to maintain its orbit by making constant adjustments.

There’s also plenty of room for improvement in solar sailing technologies. Researchers are eager to explore ideas such as the use of lasers to push at sails and the development of more sophisticated steering systems. Betts compared the LightSail program to learning to crawl, with the next wave of new technologies enabling the equivalent of walking.

In the extremely long term, one use for solar sailing is the potential to visit other star systems. Interstellar travel is still generations and generations away from being anything like a real possibility, with major technical challenges standing in the way of exploring beyond our solar system. Chemical propulsion systems like those used on the Voyager probes, the most distant man-made objects, would take tens of thousands of years to visit the nearest star systems. But spacecraft with solar sails could potentially reduce that timescale as they can continue to accelerate as they travel. “It’s the only technology we’ve got so far that shows anything resembling practical ability to do that someday,” Betts said.

As for more immediate uses, the most likely use of solar sailing isn’t that it will replace chemical propulsion systems but that it’ll be a viable option for use in certain specific missions.

“In 10 or 20 years, when people are planning a mission, they’ll think about, ‘Hey, would solar sailing work for that?’ And for some of them, it will,” Betts said. “It’ll be part of the real choices for a science mission. And that’s what we’ve contributed to with one step in the pioneering of this.”

Destruction and Renewal: Nova by Samuel R. Delany

Alan Brown

TOR BOOKS

Thu Mar 29, 2018

Cover art by Eddie Jones

In this bi-weekly series reviewing classic science fiction and fantasy books, Alan Brown looks at the front lines and frontiers of the field; books about soldiers and spacers, scientists and engineers, explorers and adventurers. Stories full of what Shakespeare used to refer to as “alarums and excursions”: battles, chases, clashes, and the stuff of excitement.

There are authors who work with the stuff of legends and make it new and fresh and all their own. There are authors who make their prose sing like it was poetry, and authors whose work explores the cosmos in spaceships, dealing with physics and astronomy. And in a few rare cases, there are authors who bring all those elements together into something magical. One of those authors is Samuel R. Delany, whose book Nova is a classic of the genre.

Delany, still in his 20s, burst onto the science fiction scene of the 1960s like a nova himself. He has been nominated for many awards, and won two Nebulas back to back in 1966 and 1967. My first exposure to his work was The Einstein Intersection, a reworking of the legend of Orpheus. My second was Nova, which became a lifelong favorite. In Nova, he created a novel that works on many levels, including myth and legend, unfolding against a solidly-researched science fiction background. There are other authors who would happily build an entire book around merely a tenth of the ideas that Delany packs into Nova. After Nova, I’ve continued to read the author’s work, and while I appreciated the craftsmanship in novels like Dhalgren and Triton, nothing ever hit my personal sweet spot like the headlong narrative rush of Nova.

What I did not know at the time, as I was not yet connected to SF fandom, and because it was not mentioned on the paperback copies of his books, was that Delany is African-American and a gay man. So he was not only winning awards (at a remarkably young age), he was breaking down barriers in the SF community, which at the time was overwhelmingly dominated by white male authors.

 

About the Author

Samuel R. Delany (born 1942) is a native of New York, who grew up in Harlem and attended the Bronx High School of Science and City College. In his younger days, he traveled the world, working in a variety of jobs before he reached the point where he could support himself with his writing. Delany became a professor in 1988 and has taught at several universities, most notably serving on the faculty of Temple University’s English Department from 2001 until he retired in 2015. He received vital support early in his career from editor Fred Pohl, and was quickly and widely acclaimed from the start of his career as a gifted and skillful author. He has won the Hugo Award twice and the Nebula award four times, collecting many more nominations for those awards over the years. In addition to Nova, his novels include Babel-17 (Nebula Award winner in 1966), The Einstein Intersection (Nebula Award winner in 1967), The Fall of the Towers, The Jewels of Aptor, and Dhalgren. Of his many short stories, “Aye, and Gomorrah…” won the Nebula Award in 1967, and “Time Considered as a Helix of Semi-Precious Stones” won both the Hugo and Nebula Awards in 1968. He won another Hugo, in the Best Related Work category, in 1989 for The Motion of Light in Water: Sex and Science Fiction Writing in the East Village 1957-1965. He was inducted into the Science Fiction and Fantasy Hall of Fame in 2002, and named as a Science Fiction Writers of America Grand Master in 2013.

Mr. Delany has been called “the first African-American science fiction writer,” a label he rejected in a New York Review of Science Fiction article in August 1998, pointing out several African-American authors before him who wrote stories that could be identified as science fiction. If not the first to write in the genre, however, he was definitely the first to make such a large and lasting impact on the genre right from the beginning of his writing career. During his career, he also came out as gay, and did not shy away from including sexual situations in his fiction. This reportedly caused some discomfort among booksellers and publishers at the time. When Mr. Delany started his career, science fiction writers and the characters they portrayed were largely male, white, and heterosexual (particularly when it came to their protagonists). Mr. Delany has been a pioneer in changing that, and helped to open the doors of the science fiction genre for the many diverse authors who followed in his footsteps.

 

The World of Nova

Cover art by Chris Moore

In the novel, which takes place in the 32nd Century CE, human civilization is split between the Earth-led worlds of Draco and the worlds of the Pleiades star cluster, where shorter travel distances have allowed a younger confederation to blossom. These powers compete in the non-aligned Outer Colonies. The economy of these worlds is controlled by a few families, whose power exceeds that of the robber barons of the United States at the end of the 19th Century. The Pleiades worlds are dominated by the Von Ray family, while the Draco worlds are dominated by the Reds of Red Shift Ltd. The Von Ray family has played a large role in keeping the Pleiades free from domination by the corporations of Draco—something that is seen as patriotism among the Pleiades, but as piracy by the people of Draco.

This future civilization is fueled by the fictional element Illyrion, a power source like none ever seen before. There is not much of this element available, but even the smallest amounts can generate huge amounts of energy. The discovery of even modest amounts of Illyrion could completely upset the balance of power among human worlds. From a scientific standpoint, while Transuranium elements tend toward faster and faster radioactive decay rates as they get heavier, scientists have long speculated that there might be “islands of stability,” where super-heavy elements such as the fictional Illyrion exist. No trace of these elements has ever been found in nature, but they remain an intriguing possibility.

Novas have long captured the imagination of those who watch the sky. The very idea of a star becoming unstable and exploding into cosmic fury—one that could destroy every world that orbits—it is both frightening and fascinating. Scientists now separate the phenomena into two types of events: classical novas, which are caused by two binary stars interacting, and supernovas, which involve a massive star exploding toward the end of its lifespan. Supernovas can reshape the elements of the star itself in a process known as nucleosynthesis.

Interstellar travel in Delany’s 32nd Century, which involves journeys at speeds faster than light, is made possible by manipulating the flow of forces unknown to us today in a process akin to sailing. These forces of the space-time continuum are accessed by energy vanes, each of which is controlled by a computer operated by the “cyborg studs” who make up the crew of a starship.

Most humans have been outfitted with cybernetic control sockets in their wrists and at base of their spines. This allows them to control a range of devices and power tools, from vacuum cleaners to mining machines and right up to starships. It also allows people to be much more flexible in moving from career to career. Some reviewers have drawn a parallel between these sockets and the jacks that would later appear as a popular element in the cyberpunk genre. But unlike those jacks, which connect people with a virtual world that stands apart from the physical world, the sockets in this novel connect people to devices in the physical world, and allow the physical world to be sensed in different ways.

 

Nova

As the novel opens, we meet a young man from Earth nicknamed The Mouse, a cyborg stud who has been knocking around the Solar System, looking for a berth aboard an interstellar ship; he’s also a musician who plays the multi-media sensory-syrynx. On a terraformed moon of Neptune, the Mouse meets a ruined and blind old man, Dan, who rants about diving into a star for Captain Lorq Von Ray. He then meets Katin, a young intellectual from Luna, and the two of them encounter Von Ray, who is not only looking for Dan, but is also looking to form a new crew. Von Ray has a hideously scarred face, and is more than a bit obsessive. The Mouse and Katin agree to join his crew, along with the brothers Lynceos and Idas, and the couple Sebastian and Tyÿ, who have amorphous, black, flying pet “gillies” accompanying them. Von Ray tells them they are heading toward a nova, attempting something that has led to failure twice before, and in a race with scions of one of Draco’s most powerful families, Prince Red and his sister Ruby Red. Poor Dan stumbles into a volcanic chasm and dies—he’s not the last character in the book that will meet a fiery fate.

The story not only charts the preparations of this crew and their voyage to their nova, but reveals Von Ray’s motivation through two long flashback scenes. The first is a childhood encounter between Lorq, Prince Red, and Ruby Red on Lorq’s homeworld. Prince Red has a birth defect that has damaged one of his arms, and wears a cybernetic prosthesis. He has been sheltered and coddled by his family to the point where he sees even a mention of his arm as a personal insult, and shows signs of a cruel and sadistic nature. Lorq is attracted to Ruby Red, who is already dominated by her brother’s forceful personality.

The second flashback involves another encounter between Lorq, Prince, and Ruby. Lorq has become an accomplished spaceship racer, and is invited by the Reds to a costume party on Earth. When he arrives, Prince gives him a pirate costume. Lorq has not paid much attention to his family history, and it falls to Ruby to explain that the pirate costume is an insult. He is again attracted to Ruby, who remains unhealthily devoted to her cruel brother. There is a confrontation, and Prince attacks Lorq, leaving him with a scarred face. Lorq returns to his family, finds out from his father that Draco is finally making inroads into the Pleiades, and that unless something changes, they will lose their independence, and his family will lose its fortune. Lorq decides to keep his facial scar as a reminder of his duty, and develops a plan to harvest Illyrion from an exploding star, upsetting the interstellar economy in the favor of the Pleiades. His first attempt, with a carefully selected crew, leaves Dan crippled, and Lorq decides to depend more on chance than planning in his second attempt.

Lorq is reckless and driven, and constantly seeks personal confrontations with Prince Red, even when they are unwise. His search for a crew in the heart of Draco is just one sign of his aggressive approach. His randomly selected crew does prove useful, as at one point Sebastian’s pets save him from Prince, and he draws inspiration and guidance from the various crew members, especially Tyÿ, who is a skilled reader of Tarot cards.

I will refrain from further summary of the plot, because if you haven’t read this book, you should do so at your earliest convenience, and I don’t want to spoil things. Suffice it to say, the nova of the title is not only a physical presence: it also represents conflict and destruction, along with renewal and rebirth.

Katin and the Mouse represent two different vehicles for the author’s viewpoint to enter the story. Delany worked as a guitarist and singer in his younger days, and Mouse represents the attitude of a performing musician, focused on senses, emotions, and the immediacy of the moment. Katin, on the other hand, is an intellectual and a Harvard graduate, and his continual note-taking for a novel he has yet to start offers a wry commentary on an author’s challenges. Katin is cleverly used as a vehicle for expository information, as he has a habit of lecturing people. The observations of Katin and the Mouse on the events of the novel are entertaining and often amusing.

Delany draws on his travels around the world, and the book is notable for the diversity of its characters and the various cultures it portrays, especially among Lorq’s crew. Lorq is the son of a mother with Senegalese heritage, while his father’s heritage is Norwegian. Mouse is of Romani heritage, Dan is Australian, Katin is from Luna, Sebastian and Tyÿ are from the Pleiades, and the twin brothers Lynceos and Idas are of African descent, with one being an albino.

Delaney explicitly evokes Tarot cards and grail quest legends in the book, but I also noted an array of other possible influences, as well. Dan reminded me of the old blind sailor Pew who sets the plot in motion in Stevenson’s Treasure Island. Von Ray’s obsession recalls Captain Ahab’s search for the white whale in Melville’s Moby-Dick. There is also a hint of Raphael Sabatini’s protagonists in Von Ray, a man driven by a need for revenge. And perhaps most strongly of all, Von Ray functions as an analog for Prometheus, striving and suffering to bring fire to his people. The book works on many levels, and is all the stronger for it.

 

Final Thoughts

Nova worked well upon my first readings, and holds up surprisingly well after fifty years. There are very few of the obvious anachronisms you often find in older works, where new developments in real life society and science have rendered the portrayed future as obsolete. The book contains interesting scientific speculation, social commentary, compelling characters, and action and adventure aplenty. I would recommend it without reservation to anyone who wants to read an outstanding science fiction novel.

And now, as I always do, I yield the floor to you. Have you read Nova, and if so, what did you think? What are your thoughts on other works by Delany? And how do you view his work in terms of the history of the science fiction field?

Alan Brown has been a science fiction fan for over five decades, especially fiction that deals with science, military matters, exploration and adventure.